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<div class="moz-cite-prefix">On 29/03/2019 22:03, Adrien André
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:4c53cc42-6e72-9429-3f37-eaa1936108c8@laposte.net">Hello,
<br>
<br>
following the wiki doc about stream extraction [1], once the
stream layer thinned and vectorized,
<br>
there are many small arcs i would like to remove (see attached
capture [2]).
<br>
<br>
So, with the underlying drainage direction map [3], and the
resolution r, i would like to delete segments
<br>
- about r*sqrt(2) long
<br>
- whose azimuth is more than 45° different from the pixel value
under its starting point.
<br>
<br>
</blockquote>
<p><br>
</p>
<p>This might be possible, but I think the best approach would be to
choose the correct threshold value for r.watershed from the start.
</p>
<p>Trying to manually "fiddle" with the stream network will most
likely leave you with disconnected segments, or other
inconsistencies.</p>
<p><br>
</p>
<blockquote type="cite"
cite="mid:4c53cc42-6e72-9429-3f37-eaa1936108c8@laposte.net">But i
still haven't figured a way to achieve this.
<br>
<br>
Do you have any advice ?
<br>
<br>
Thank you,
<br>
<br>
Best regards,
<br>
<br>
[1]
<a class="moz-txt-link-freetext" href="https://grasswiki.osgeo.org/wiki/Creating_watersheds#Display_first_results">https://grasswiki.osgeo.org/wiki/Creating_watersheds#Display_first_results</a><br>
[2] <a class="moz-txt-link-freetext" href="https://framapic.org/1exdxrdqxemw/ytuVxiBp2FKh.png">https://framapic.org/1exdxrdqxemw/ytuVxiBp2FKh.png</a>
<br>
[3] <a class="moz-txt-link-freetext" href="https://grass.osgeo.org/grass74/manuals/r.watershed.html">https://grass.osgeo.org/grass74/manuals/r.watershed.html</a>
<br>
<br>
<br>
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<pre class="moz-quote-pre" wrap="">_______________________________________________
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</blockquote>
<pre class="moz-signature" cols="72">--
Micha Silver
Ben Gurion Univ.
Sde Boker, Remote Sensing Lab
cell: +972-523-665918</pre>
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